Sometimes as we grow as musicians we develop a taste for a more polished sound. In terms of chords, our taste might shift from simple triads to seventh chords, until we get to extended chords. Today, I'd like to explore this last area, which seems to be a bit more obscure.
1. About Extended Chords and Intervals
In order to understand extended chords, we need to start with intervals. All the intervals between the root and the octave are called simple intervals. Once we get beyond the octave, we build the intervals by adding a simple interval to an octave. Those intervals are called compound intervals.
The quality of the simple interval remains the same when it is added to the octave. For instance, a perfect fourth added to an octave becomes a perfect eleventh.
When we apply this theory concept to a chord, the compound interval will be the extension of our chord. As for intervals, adding an extension won't change the quality of the chord, or its function in a progression. In fact, the reason why we want to add the extension is just to spice up the chord progression. We won't cover tenths and twelfths in this tutorial, as they don't affect the chord in any way.
It's important to understand how to name and label these chords, so that when you encounter one on a chart you will know which notes form that chord. There are two basic principles that musicians regularly mess up:
- Extended chords are named after the largest interval. If a chord contains both the 9th and the 11th, it's called an eleventh chord.
- A seventh chord with an extension is called by the largest extension, no matter in which octave the extension is placed. So if you have a Cmaj7 and then you add a "D" note, it will function as a nine whether it is in the upper or lower register.
2. How to Build Extended Chords
Let's take a closer look at these chords. Whenever you want to build an extended chord, you need to add an extension to a seventh chord. If a chord doesn't contain any kind of seventh, it can't be called extended.
9th chords are really popular, and sort of sweetening. They have a certain color that doesn't alter the sound of a chord, but makes it smoother and softer.
Here's an audio example using 9th chords, and some fingerings:
The next extension we can add to a 7th chord is the fourth, which functions as an 11th. There's an exception though. In a major scale, the distance between the major third and the fourth is a half step: not a pleasant sound. If you add the a perfect fourth to a major seventh chord, you will have harsh clashes between these two notes.
So, you don't have to take this as a rule, but 90% of the time you have a major seventh chord, you'll add a #11 which is, in fact, a whole step away from the third.
Again, an audio sample and some guitar fingerings:
On a guitar, there is one exception of a maj11 chord that actually sounds good, and not so awkward. The reason is the way it's voiced.
The last extension you can actually add to the 7th chord is the sixth, which functions as a 13th. Keep in mind that even if you have a minor chord, you will add a major sixth. In these cases, the chords will imply a Dorian harmony. So, yes, you can play a dorian scale from the root of a minor sixth chord, and it will sound appropriate.
Here's an audio sample and some guitar fingerings:
3. Playing Extended Chords in Context
Let's now apply the concept of extended chords. Here's a basic progression in the key of C. Let's take a look at it:
If we jack all the chords up to seventh chords, here's what we get:
Now, I want to give you three different versions of the same progression, starting with 9th chords, then 11th, then 13th. This is a totally theory-oriented approach, and of course, in the end, everything has to be judged by your ear more than by your knowledge, so make sure to train your ear to those sounds as well.
Let's start with 9th chords:
The Emin9 is the odd chord in this progression. That's because the nine of Emin chord is F#, which is not in the key of C. So you need to be careful: Whenever you use an extended chord, remember that you might use notes that are out of key.
It may sound good, it may not. You could play Emin(b9) to have an F note, but then the chord itself would sound really bad, because of the clashes between E and F. My personal choice, if you wish to stay diatonic, would be to keep Emin7.
Let's bring it to the 11th universe and see what happens.
Here, I made some different choices based on where the chord was placed in the progression. I open up with the Cmaj11, which is not a pleasant sound, and then G11 which keeps the tension of the previous chord. Although it makes more sense harmonically since it's the V chord and it has to a push towards the I.
The next two minor chords fit perfectly in the progression. Then I raised the fourth on the Fmaj chord. Notice how much smoother this chord is when you compare to the Cmaj11 at the beginning.
Finally, I ended on the Cmaj, but this time raising the fourth again. The result is sort of suspended sound, that might work out great in a fusion context.
Finally, let's deal with 13th chords.
In this version of the progression, we don't encounter any issues until the first minor chord. Remember that when you have to add a major sixth to the minor chord. A sixth away from A is F# which, again, is not in the key.
The next chord does the same thing. The major sixth of Emin is C#, which would be a #1—not really the extension you were after. The choice of keeping those chords or not really depends on style and personal taste.
When I played these progressions on my guitar, most of time I avoided intervals such as the fifth. That has to be done on guitar, since you only have four fingers (maybe five if you are a thumb guy). Playing these chords on keyboard definitely gets a better result, in my opinion.
Also, it has to be said that, in a band context, the guitar player may play just the third and the extension of the chord, while the bass player keeps the root, and the piano player fills the chord out. That's not the only configuration you can have: sometimes singers sing the extension of a chord.
The idea of using extended chords can really open up your chord vocabulary. It's important to tune your ear to these kinds of sounds: it can beneficial when you compose, and also helps you come up with cool arrangements for someone else's songs.
Extended chords require a good understanding of harmony, rather than learning some guitar shapes. But if you commit to it, this can be another ace in the hole.